Statistics Questions

Archie is fed up with waiting in line at his local post office and plans to contact his congresswoman Archie knows that his complaint will not be well received without data to back it up So to improve his case over the next few months Archie records the waiting time for a selection of 26 post office visits made by him and other customers These waiting times in minutes are summarized in the following frequency distribution Waiting time in minutes 0 to 6 7 to 13 14 to 20 21 to 27 28 to 34 Frequency 2 9 6 6 3 Based on the frequency distribution using the midpoint of each data class estimate the mean waiting time for the data Archie collected For your intermediate computations use four or more decimal places and round your answer to one decimal place

The following data lists the ages of a random selection of actresses when they won an award in the category of Best Actress along with the ages of actors when they won in the category of Best Actor The ages are matched according to the year that the awards were presented Complete parts a and b below 25 Actress years 30 Actor years 58 40 33 29 32 25 23 41 31 35 32 41 28 35 54 43 38 46 a Use the sample data with a 0 01 significance level to test the claim that for the population of ages of Best Actresses and Best Actors the differences have a mean less than 0 indicating that the Best Actresses are generally younger than Best Actors In this example is the mean value of the differences d for the population of all pairs of data where each individual difference d is defined as the actress s age minus the actor s age What are the null and alternative hypotheses for the hypothesis test Ho Hd year s year s H Ha Type integers or decimals Do not round

Level of Confidence 1 x 100 90 95 99 Area in Each Tail 0 05 0 025 0 005 a 2 Critical Value Z 2 1 645 1 96 2 575 People were polled on how many books they read the previous year Initial survey results indicate that s 11 7 books a How many subjects are needed to estimate the mean number of books read the previous year within four books with 95 confidence This 95 confidence level requires enter your response here Round up to the nearest subject

Question 8 of 16 8 Will the critical value of the hypothesis H0 p 0 35 vs H1 p 0 35 be positive or negative OPositive ONegative

Question 2 of 16 2 A random sample of 36 individuals is obtained from a large population with a known standard deviation of o 4 9 If the sample mean is observed to be 23 22 test H0 25 versus the alternative H1 25 using the classical approach at the 0 02 level of significance What is the value of the test statistic Round your answer to the nearest hundredths Answer

Use the following select financial information to prepare a December 31 balance sheet 64 400 Total equity 40 000 Accounts payable 29 000 Salaries payable 77 000 Unearned revenue Cash Accounts receivable Supplies Land Balance Sheet Total Equity 166 000 32 000 3 200 9 200

4 A greenhouse in a tri county area has kept track of its customers for the last several years and has determined that 28 of its customers plant a vegetable garden in the spring The greenhouse obtains a random sample of 1000 of its customers a What is the mean and standard deviation of the sampling distribution of p the sample proportion of customers that plant a vegetable garden in the spring b What is the probability that more than 30 of its customers plant a vegetable garden in the spring Draw and label a curve and then give your answer c What is the probability that between 25 and 32 of its customers plant a vegetable garden in the spring Draw and label a curve and then give your answer

2 A physical fitness association is including the mile run in its secondary school fitness test The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 480 seconds and a standard deviation of 35 seconds a Find the probability that a randomly selected boy in secondary school can run the mile in less than 400 seconds Draw and label the curve and then answer the question Then give the percentage application of your answer b Find the probability that a randomly selected boy in secondary school will take more than 510 seconds for the run Draw and label the curve and then answer the question Then give the percentage application of your answer

3 The board of examiners that administers the real estate broker s examination in a certain state found that the mean score on the test was 452 and the standard deviation was 62 If the board wants to set the passing score so that only the best 80 of all applicants pass what is the passing score Assume that the scores are normally distributed Draw and label a curve and then give your answer

For each situation draw and label the area represented under the normal curve Then compute the probability Assume that that u 85 d 7 a Compute P x 92 b Compute P x 70 c Compute P 72 x 95

11 Using the matched pairs data below calculate s where d Y X X 7 28 7 65 6 85 8 07 5 55 8 00 8 26 8 14 Y 10 59 8 21 10 01 9 75 11 97 12 21 11 87 11 20 Round your answer to the nearest thousandths Answer

10 Using the matched pairs data below calculate d where d Y X X 6 91 9 22 9 38 9 26 9 40 8 51 7 64 6 88 Y 10 82 4 60 12 19 6 96 9 07 7 25 10 17 9 57 Round your answer to the nearest thousandths Answer

An association of Realtors reports state by state median existing home prices for each quarter Why do you supp they use the median instead of the mean What might be the disadvantage of reporting the mean Choose the correct answer below OA Home prices are discrete data and the median should always be reported instead of the mean for discrete data Reporting the mean would have the disadvantage of being more difficult to interpret OB Home prices are probably skewed to the left and not symmetric This makes the median a better representatio of the center than the mean which would be influenced by the extremely low priced homes Reporting the mea would give the impression that the typical home price is lower than it is OC Home prices probably have a symmetric distribution which makes the median a better representation of the center than the mean Reporting the mean would give the impression that the typical home price is much lower or higher than it actually is O D Home prices are probably skewed to the right and not symmetric This makes the median a better representation of the center than the mean which would be influenced by the extremely high priced homes Reporting the mean would give the impression that the typical home price is higher than it is

Question 6 of 6 6 Test H0 P P 0 versus H1 P P 0 using the p value approach at the 0 02 level of significance given the following summary statistics of two independent random samples P 0 50 P 0 46 n 360 and n 400 What is the p value Round your answer to the nearest thousandths Answer

Question 4 of 6 4 Test H0 P 1 P 0 versus H1 P P 0 using the classical approach at the a 05 level of significance given the following summary statistics of two independent random samples P 0 30 P 0 25 n 300 and n 400 Do you have sufficient evidence to reject the null hypothesis OYes ONO

2 Construct a 98 confidence interval to test H0 P P2 0 versus H1 P P 0 using the confidence interval approach at the 0 02 level of significance given the following summary statistics of two independent random samples p 0 40 P 0 35 n 200 and n 240 What is the left endpoint of the confidence interval Round your answer to the nearest thousandths Answer Continue Reset answer

Use the information below to construct the appropriate confidence interval P P to test H0 P P 0 vs H1 p P 0 at the a 0 01 level of significance What is the left endpoint of the confidence interval used in this test Round your answer to the nearest hundredths x 35 x 38 n 60 n 80 Fill in the correct answer Check Answer

Question 1 of b 1 Construct a 95 confidence interval for p p given the following summary statistics of two independent random samples P 0 54 p 0 48 n 200 and n 225 What is the left endpoint of the confidence interval Round your answer to the nearest thousandths Answer

Use the Relationship Between the F Test Statistic and the P value flow chart interactive to answer the following question In a test of analysis of variance the F test statistic is large and the P value is small Which of the following conclusions is best Choose the correct answer below A There is sufficient evidence to support the claim that the samples are from populations having means that are all different OB There is sufficient evidence to support the claim that the samples are from populations having means that are not all the same OC There is not sufficient evidence to reject the claim that the samples are from populations having means that are all equal OD There is sufficient evidence to support the claim that the samples are from populations having means that are all equal

Twelve different video games showing alcohol use were observed The duration times of alcohol use were recorded with the times seconds listed below What requirements must be satisfied to test the claim that the sample is from a population with a mean greater than 75 sec Are the requirements all satisfied 87 15 568 51 0 60 192 46 166 0 2 www What requirements must be satisfied Select all that apply A The sample observations must be a simple random sample B Either the population is normally distributed or n 30 or both C At least one observation must be above or below 75 sec D The conditions for a binomial distribution must be satisfied 58

A genetic test is used to determine if people have a predisposition for thrombosis which is the formation of a blood clot inside a blood vessel that obstructs the flow of blood through the circulatory system It is believed that 3 of people actually have this predisposition The genetic test is 98 accurate if a person actually has the predisposition meaning that the probability of a positive test result when a person actually has the predisposition is 0 98 The test is 97 accurate if a person does not have the predisposition What is the probability that a randomly selected person who tests positive for the predisposition by the test actually has the predisposition Round your answer to four decimal places

3 Use the results from a survey of a simple random sample of 1039 adults Among the 1039 respondents 67 rated themselves as above average drivers We want to test the claim that of adults rate themselves as above average 5 drivers Complete parts a through c www a Identify the actual number of respondents who rated themselves as above average drivers Round to the nearest whole number as needed

Assume a significance level of 0 01 and use the given information to complete parts a and b below Original claim The mean pulse rate in beats per minute of a certain group of adult males is 68 bpm The hypothesis test results in a P value of 0 0085 a State a conclusion about the null hypothesis Reject Ho or fail to reject Ho Choose the correct answer below OA Fail to reject Ho because the P value is less than or equal to a OB Reject Ho because the P value is greater than C Reject Ho because the P value is less than or equal to OD Fail to reject Ho because the P value is greater than x b Without using technical terms state a final conclusion that addresses the original claim Which of the following is the correct conclusion OA There is sufficient evidence to warrant rejection of the claim that the mean pulse rate in beats per minute of the group of adult males is 68 bpm OB There is not sufficient evidence to warrant rejection of the claim that the mean pulse rate in beats per minute of the group of adult males is 68 bpm C The mean pulse rate in beats per minute of the group of adult males is 68 bpm D The mean pulse rate in beats per minute of the group of adult males is not 68 bpm

Assume a significance level of a 0 01 and use the given information to complete parts a and b below Original claim The mean pulse rate in beats per minute of a certain group of adult males is 68 bpm The hypothesis test results in a P value of 0 0085 a State a conclusion about the null hypothesis Reject Ho or fail to reject Ho Choose the correct answer below OA Fail to reject Ho because the P value is less than or equal to a OB Reject Ho because the P value is greater than a OC Reject Ho because the P value is less than or equal to a D Fail to reject Ho because the P value is greater than a

Identify the type I error and the type Il error that corresponds to the given hypothesis The proportion of people who write with their left hand is equal to 0 32 Which of the following is a type I error OA Fail to reject the claim that the proportion of people who write with their left hand is 0 32 when the proportion is actually different 0 32 OB Fail to reject the claim that the proportion of people who write with their left hand is 0 32 when the proportion is actually 0 32 C Reject the claim that the proportion of people who write with their left hand is 0 32 when the proportion is actually different from 0 D Reject the claim that the proportion of people who write with their left hand is 0 32 when the proportion is actually 0 32

The following questions refer to the standard normal distribution A The standard normal distribution is a symmetric curve with a mean of 0 O True False B The z score corresponding to a number below the mean is postive True O False C The area to the left of z 0 is negative O True O False D Which of the following is not true about the standard normal curve O It s uniform O It s continuous

1 A What is the probability that x is less than 4 O 5 8 02 8 9 O 3 8 O correct answer is not given B What is the 90th percentile 09 2 07 2 08 2 O correct answer is not given

A uniform distribution is shown below 1 What is the standard deviation of this distribution O 2 54 2 89 O 2 31 9 correct

1 9 What is the mean of the distribution O 4 5 05 O 5 5 O correct answer is not given

Use the accompanying radiation levels in Find the percentile P25 P25 for 50 different cell phones kg W Type an integer or a decimal Do not round kg 0 21 0 28 0 33 0 47 0 55 0 57 0 58 0 69 0 70 0 83 0 86 0 89 0 91 0 93 0 95 0 96 0 97 0 98 1 08 1 11 1 12 1 13 1 14 1 14 1 17 1 19 1 20 1 20 1 20 1 22 1 24 1 25 1 25 1 25 1 25 1 26 1 28 1 29 1 36 1 36 1 38 1 39 1 41 1 42 1 45 1 46 1 46 1 50 1 52 1 55

W corresponding to 0 81 kg EEE Click the icon to view the radiation levels W The percentile corresponding to 0 81 is kg Round to the nearest whole number as needed Radiation Levels 0 62 0 64 0 79 0 81 0 98 1 01 1 07 1 08 0 24 0 26 0 29 0 48 0 60 0 61 0 87 0 89 0 93 0 93 0 94 0 96 1 09 1 11 1 11 1 12 1 14 1 16 1 22 1 25 1 26 1 27 1 17 1 18 1 19 1 21 1 27 1 27 1 28 1 29 1 32 1 32 1 32 1 37 1 37 1 44 1 45 1 49 1 49 1 51 1 53 1 55 X

ourteen different second year medical students at a hospital measured the blood pressure of the same erson The systolic readings mm Hg are listed below Use the given data to construct a boxplot and dentify the 5 number summary 122 121 144 135 A OC The 5 number summary is 120 122 126 5 140 and 150 all in mm Hg Use ascending order Type integers or decimals Do not round Which boxplot below represents the data 120 120 125 120 140 130 Blood Pressure mm Hg 140 130 Blood Pressure mm Hg 150 146 150 Q Q 130 126 122 123 Q OB O D 120 120 140 127 150 130 140 Blood Pressure mm Hg 130 140 Blood Pressure mm Hg 150 150 Q Q C

e the accompanying radiation levels TO W W for 50 different cell phones Find the percentile P70 kg Type an integer or decimal rounded to two decimal places as needed 0 21 0 86 1 09 1 24 1 31 0 23 0 89 1 09 1 24 1 34 0 27 0 90 1 10 1 25 1 40 0 46 0 92 1 12 1 27 1 41 0 61 0 94 1 15 1 27 1 45 0 62 0 94 1 15 1 28 1 45 0 63 1 00 1 16 1 29 1 46 0 64 1 02 1 17 1 30 1 49 0 75 1 06 1 18 1 31 1 53 0 8 10 1 2 13 1 5

In a particular survey of internet users 3517 respondents say that they use social networking sites and 1332 respondents say that they do not use social networking sites What is the probability that a randomly selected person uses a social networking site Does that result suggest that it is likely with a probability of 0 5 or greater for someone to use social networking sites The probability that a randomly selected person uses a social networking site is Round to three decimal places as needed

2 The college bookstore tells prospective students that the average cost of its textbooks is 52 with a standard deviation of 4 50 A group of smart statistics students thinks that the average cost is higher In order to test the bookstore s claim against their alternative the students will select a random sample of size 100 Assume that the mean from their random sample is 54 80 Perform a hypothesis test at the 5 level of significance z critical 1 96 and state whether we accept or reject the null hypothesis

In a survey of U S adults with a sample size of 2040 362 said Franklin Roosevelt was the best president since World War II Two U S adults are selected at random from this sample without repl Complete parts a through d a Find the probability that both adults say Franklin Roosevelt was the best president since World War II The probability that both adults say Franklin Roosevelt was the best president since World War II is Round to three decimal places as needed b Find the probability that neither adult says Franklin Roosevelt was the best president since World War II The probability that neither adult says Franklin Roosevelt was the best president since World War II is Round to three decimal places as needed c Find the probability that at least one of the two adults says Franklin Roosevelt was the best president since World War II The probability that at least one of the two adults says Franklin Roosevelt was the best president since World War II is Round to three decimal places as needed d Which of the events can be considered unusual Explain Select all that apply None of these events are unusual The event in part c is unusual because its probability is less than or equal to 0 05 The event in part a is unusual because its probability is less than or equal to 0 05 The event in part b is unusual because its probability is less than or equal to 0 05

Question 4 of 7 4 Test HO H H 0 versus H1 0 at the 0 05 level of significance using the classical approach given the following summary statistics of randomly sampled matched pairs data d 0 96 s 2 18 and n 22 Assume the differences are approximately normally distributed What is the test statistic Round your answer to the nearest hundredths Answer Continue Im Reset answer

possible This question 1 point s possible 4 663 The probability of selecting an eight and then selecting a five is Round to three decimal places as needed Submit Two cards are selected from a standard deck of 52 playing cards The first card is not replaced before the second card is selected Find the probability of selecting an eight and then selecting a five

Click the icon to view the data on business degrees and female students in a particular country who received bachelor s degrees in business in a recent year Complete parts a and b below a Find the probability that a randomly selected student is male given that the student received a business degree The probability that a randomly selected student is male given that the student received a business degree is 0 534 Round to three decimal places as needed b Find the probability that a randomly selected student received a business degree given that the student is female The probability that a randomly selected student received a business degree given that the student is female is 0 466 Round to three decimal places as needed Business Graduates Male Female Total W Business degrees Nonbusiness degrees 185 138 161 362 346 500 612 098 860 323 1 472 421 possible X Total D 797 236 1 021 685 1 818 921 S

Question 3 of 3 Test HO H H 0 versus H1 0 at the 0 05 level of significance using the confidence interval approach given the following summary statistics of randomly sampled matched pairs data d 1 44 s 2 52 and n 20 Assume the differences are approximately normally distributed What is the left endpoint of the interval Round your answer to the nearest thousandths Answer Continue Reset answer

1 Using the matched pairs data below calculate d where d Y X X 11 87 11 77 10 91 11 79 14 76 12 41 13 13 12 35 Y 11 85 14 77 13 50 14 13 15 48 13 74 15 55 17 16 Round your answer to the nearest thousandths Answer

5 How often should person centered plans be updated O Annually Bi annually Once each month On an ongoing basis

K A frequency distribution is shown below Complete parts a and b The number of televisions per household in a small town Televisions 0 1 2 3 C Households 23 442 720 1405 a Use the frequency distribution to construct a probability distribution P x X 0 1 2 3 Round to three decimal places as needed b Graph the probability distribution using a histogram Choose the correct graph of the distribution below OA AP x 0 6 0 5 0 4 0 3 0 2 0 1 0 1 2 3 of Televisions X In chane Choose the correct answer below B AP x 0 6 0 5 0 4 0 3 0 2 0 1 3 0 1 2 of Televisions O O C AP x 0 6 0 5 0 4 0 3 0 2 0 1 01 of Telev

This question 1 point s possible Sixty five percent of men consider themselves knowledgeable football fans If 14 men are randomly selected find the probability that exactly six of them will consider themselves knowledgeable fans OA 0 051 OB 0 176 OC 0 650 OD 0 429

In a recent survey 80 of the community favored building a police substation in their neighborhood If 15 citizens are chosen what is the mean number favoring the substation OA 10 B 12 O C 15 OD 8

K Identify the sample space of the probability experiment and determine the number of outcomes in the sample space Draw a tree diagram Determining a person s letter grade A B C D F and gender male M female F Identify the sample space OA AM AF BM BF CM CF OB AM AF BM BF CM CF DM DF FM FF OC AM AF AB BM BF BB CM CF CB OD AM AF AB BM BF BB CM CF CB DM DF DB There are outcomes in the sample space Choose the correct tree diagram below OA O C A B MFBMFBMFBMFB B C C D D F MF M F M F M F M F OB O D tion 1 point s possible A B MFBM FBM A B C r MFMF M

Tale and female students in a particular country who received bachelor s degrees in business in a recent year Complete parts a and b below Click the icon to view the data on business degrees CITE a Find the probability that a randomly selected student is male given that the student received a business degree The probability that a randomly selected student is male given that the student received a business degree is Round to three decimal places as needed b Find the probability that a randomly selected student received a business degree given that the student is female The probability that a randomly selected student received a business degree given that the student is female is Round to three decimal places as needed Business Graduates Male Female Total Business degrees Nonbusiness degrees 185 138 612 098 161 362 860 323 346 500 1 472 421 Total 797 236 1 021 685 1 818 921 X O

Question 2 of 6 2 How many critical values will the hypothesis test H0 p20 40 vs H1 p 0 40 have Answer Previous Answer 1

Z 0 0 0 1 0 2 plete parts a through d A research institute poll asked respondents if they felt vulnerable to identity theft In the poll n 1001 and x 519 who said yes Use a 95 confidence level Click the icon to view a table of z scores dard Normal 2 Distribution a Find the best point estimate of the population proportion p Round to three decimal places as needed 0 z 00 5000 5398 5793 Cumulative Area from the LEFT 01 5040 5438 5832 02 5080 5478 5871 POSITIVE z Scores 03 5120 5517 5910 www 04 5160 5557 5948 05 5199 5596 5987 06 5239 5636 6026 07 5279 5675 6064 08 5319 5714 6103 nswer

A company manufacturing cell phones surveys daily users The results 600 irs in thousands y 500 Mobile Users in thousands 400 300 TROT NAAILL 400 300 200 100 0 On which day Day 9 Daywise Mobile Users 4 7 y 32x 42 Number of Days Number of Days Question navig 14 12 10 the number of users reach 300 0007 7 51 16 7 51